Schizophrenia affects approximately 1% of the population. It is characterized by the presence of positive symptoms (unusual thoughts or perceptions, including hallucinations and delusions), negative symptoms (social withdrawal, lack of pleasure in everyday life), and impaired cognitive functions (verbal memory, information processing). Such symptoms may be indicative of other disorders, such as, for example, bipolar disorder.
A number of antipsychotic drugs have been approved to treat schizophrenia. However, patient response to treatment remains highly variable, and the discontinuation rate with antipsychotic treatment is high. No single antipsychotic agent offers optimal effect for every patient with schizophrenia. Few data are available to guide clinicians and patients in the selection of the most appropriate medication and in the improvement of treatment specificity for an individual patient. Pharmacogenomics provides the opportunity to discover genetic markers predictive of response. Knowing how a patient with schizophrenia might respond to a particular therapy based on his or her genetic makeup may enable clinicians to select the most optimal drug and dosage with less trial and error.